The two versions of the WRF developed by Mike Leuthold are quite different in their details today. Specific point forecasts for many spots would be very different, depending up the version used. This is not surprising, since the back ground forcing is nearly non-existent and the mountains are driving the development of storms. The storms then evolve in their own ways within each model's thermodynamic environments. I show just two examples from each model here as illustration.
Above is the forecast of 10-m winds from the WRF-GFS valid at 7 pm this evening. The GFS version produces a strong mesohigh near the pass between Tucson and Benson, with very strong outflow winds impacting both eastern Pima County and much of Cochise County. The NAM version (below - 10 m winds at 5 pm this afternoon) produces strong outflows in western and central Pima County that extend into Maricop and Pinal Counties, with strong winds also over much of Cochise County.
Here are the forecasts of total rainfall through 6 am tomorrow (8 Jul 13) with the GFS version above and the NAM version below. The GFS version is much wetter, especially from Tucson east (but remember that the NAM has been the better forecast the last several days - will this be the case again today?). One interesting feature in the GFS version is that the model forecasts a distinct MCV (Mesoscale Convective Vortex) that is spinning away in middle-levels near Safford at sunrise. Best thing to do today is to keep an eye on your local developments - however, both models forecast minimal activity directly over Metro Tucson although the winds at the airport are markedly different later today.
No comments:
Post a Comment